Re: ST7789V2 LCD Controller

[Bod]

Not wanting to delve into C programming just yet (I had to do some C++ at uni and didn't get very far!), I have been trying to approach the problem with just Perl. This is what I have got.

use strict;
use warnings;
use RPi::SPI;

# Initialize SPI: bus 0, 8 MHz
my $spi = RPi::SPI->new(0, 8000000);

# Reset display (if necessary)
sub reset_display {
    # Handle reset
}

# Send command to the display
sub send_command {
    my ($cmd) = @_;
    my $data = \[ $cmd ];  # Create an array reference for a single co
+mmand byte
    print "Sending command\n";
    $spi->rw($data, 1);  # Send command via SPI
}

# Send data to the display (ensure data is an array reference)
sub send_data {
    my ($data_ref) = @_;
    print "Sending data\n";
    $spi->rw($data_ref);  # Send data via SPI
}

# Initialize the display (according to the display's datasheet)
sub init_display {
    send_command(0x01);  # Command: software reset

}

reset_display();
init_display();

I'm getting an error from $spi->rw($data, 1); that doesn't seem to make sense. The error is data param must be an array reference but the RPi::SPI documentation says that rw takes buf (arrayref) and len (integer). It doesn't mention a data parameter and I am giving it an arrayref and an integer!

I've searched the source code and the error text is not there.

Some help debugging this would be appreciated please

[tybalt89]

my $data = \[ $cmd ];  # Create an array reference for a single comman
+d byte

should be

my $data = [ $cmd ];  # Create an array reference for a single command
+ byte

You were sending a reference to a reference to an array :(